Machine for vacuum packaging various products in particular for vacuum packaging food products

ABSTRACT

Vacuum packaging machine for food products, having conveyer means conveying a tape of moldable plastics to a vacuum forming station where depressions are vacuum formed in said tape for receiving the food products in such depressions. After a filling station where the food products are introduced into the depressions there is provided an evacuation closing and welding station, where filled depressions are covered by a tape of plastics material with the interposition of a suction mouth between the covering tape and one of the edges of the depressions, which evacuates the filled depressions while a welder welds the covering tape along the edges of the depression. A cutting assembly separates afterwords the closed and evacuated depressions.

United States Patent 1 Tartarini [451 .lluly 17,1973

[ MACHINE FOR VACUUM PACKAGING VARIOUS PRODUCTS, IN PARTICULAR FORVACUUM PACKAGING FOOD PRODUCTS [76] Inventor: Cesare Tartarini, ViaColombo 9,

Zola Predosa, Italy [22] Filed: Sept. 7, 1971 [30] Foreign ApplicationPriority Data Sept. 11,l970' Italy .................L.........3546A/70[21] Appl. No.: 178,001

[52] US. Cl 53/112 A [51] Int. Cl B65b 31/02 [58] Field or Search .i53/112 A [56] References Cited UNITED STATES PATENTS 3,164,934 11/1965 7Pancratz 53/112 A 3,061,984 11/1962 Mahaffy 53/112 A X Primary Examiner-Travis S. McGehee Attorney-Guido Modiano and Albert Josif [57]ABSTRACT Vacuum packaging machine for food products, having conveyermeans conveying a tape of moldable plastics to a vacuum forming stationwhere depressions are vacuum formed in said tape for receiving the foodprod ucts in such depressions. After a filling station where the foodproducts are introduced into the depressions there is provided anevacuation closing and welding station, where filled depressions arecovered by a tape of plastics material with the interposition of asuction month between the covering tape and one of the edges of thedepressions, which evacuates the filled depressions while a welder weldsthe covering tape along the edges of the depression.

A cutting assembly separates afterwords the closed and evacuateddepressions.

3 Claims, 4 Drawing Figures MACHINE FOR VACUUM PACKAGING VARIOUSPRODUCTS, IN PARTICULAR FOR VACUUM PACKAGING FOOD PRODUCTS BACKGROUND OFTHE INVENTION The present invention relates to a machine for vacuumpackaging various products, in particular for vacuum packaging foodproducts. Machines for vacuum packaging presently available generallycomprise a pneumatic chamber inside which the packages which have beenpreviously partially prepared are evacuated. Because of the presence ofthe pneumatic chamber, which is always very heavy, the operational speedis necessarily very low because the operations relating to the chambercan only be carried out slowly. In machines comprising chambers there isa further limiting factor in the form of the dead spaces which alwaysremain inside the chamber, and which give rise to the necessity of usingpumps of very high capacity if evacuation times are to be reduced as lowas possible.

A further grave disadvantage of chamber machines is that the productcontainer must include a certain excess of the material used for formingthe package, at least on part of its edges, so as to allow the memberswhich grip the packages to operate and to facilitate the working of thecomponents which separate the various packages.

Because of the high quality and consequent cost of the material used forthe enclosures in vacuum packaging, this disadvantage results in a graveburden.

A further disadvantage of present machines for vacuum packaging is thatthey are not suitable for handling products whose shapes or dimensionsare widely dispersed, in that they give rise to packages of particularlybad appearance because of wrinkles and curling, and also accentuate theformer disadvantage of wide margins for ensuring a gripping surface.

SUMMARY OF THE INVENTION The object of the present invention is toprovide a machine for vacuum packaging various products and inparticular food products, which substantially obviates theaforementioned disadvantages of machines presently available, and whichis able to work at high speed on products of any shape in that itcomprises no appreciable dead space which might unduly lengthen workingtimes.

This object is attained according to the invention by a machine forvacuum packaging various products and in particular food products,comprising means for supporting and guiding a pair of bands whichapproach each other longitudinally and fonn the packages, weldingmembers lowered on to and raised from the bands for welding themtransversally and longitudinally after introducing the products betweenthem, and means for cutting the individual packages, characterised inthat it comprises a suction port of flat structure disposed upstream ofthe transversal welding members and penetrating between the approachingportions of the bands welded along their lateral edges, means fordriving said port with reciprocating motion parallel to the bands andcooperating with the means which operate the transversal welding membersso as to withdraw the port during lowering of said welding members.

BRIEF DESCRIPTION OF THE DRAWING Further details of the invention willbe more evident from the detailed description of one embodimentillustrated in the accompanying drawing in which:

FIG. 1 is a partially diagrammatical longitudinal view of the machine;

FIG. 2 shows on an enlarged scale the working members of the machine,predisposed for evacuating and welding the packages;

FIG. 3 is a plan view of the members shown in FIG. 2, and

FIG. 4 is a cross-section through the machine at the working zone of thelongitudinal welders.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the Figures the samecomponent part or detail is in each case indicated by the same referencenumeral, and they show the main assemblies of the machine, 1, 2, 3 and4, namely the assembly for forming the band which will form the lowerpart of the package, the vacuum assembly, the organs for longitudinallyseparating the completed packages, and the cutting assembly fortransversally cutting the packages respectively.

The assembly 1 forms on a band 5, which is unwound from a reel 6,depressions into which the product is introduced. The assembly 1comprises a pair of members 7 and 8 between which the band 5 passes, thefirst constituting the forming die and the second a radiation heatingcomplex which brings that section of band 5 opposite it to the plasticstate.

The member 7 comprises substantially a body with a certain number ofdepressions or cavities (4 in the example illustrated) which producethat number of depressions in the band 5. The body 7 comprises a pair oflugs 9 pivoted to a shaft 10 about which said body can rotate through acertain angle by means of cams which co-operate with levers andconnecting rods connected to the arm 9a. The cavities in the body 7 areconnected by connectors 11 to a manifold 12 which is connected in itsturn by a flexible pipe and valve means to the suction nozzle of acommon vacuum pump. The member 8 comprises a hollow body with dimensionsapproximately corresponding to those of the body '7. It carries heatingmeans and comprises lugs 13 by which it is pivoted to a shaft 14. Themember 8 can also turn about the shaft 14 by means of cams co-operatingwith levers and connecting rods connected to the arm 13a.

The assembly I is completed by a mask 15 fixed to the frame of themachine, and a roller 16 idly pivoted on the shaft 10 for supporting theband 5. The mask 15 comprises a central opening corresponding to theworking parts of the members 7 and 8, and protects those parts of theband 5 which are not to be shaped from thermal radiation. Following theassembly for forming the depressions there is a loading station for theproduct to be packaged in the depressions. Said loading stationcomprises a roller 18 about which the preformed band partially windsuntil it rests on a conveyor 19. The roller 18 for deviating the band issupported on a shaft 20 and comprises a tubular core 21 and a series ofprotuberances 22 fixed to said core which form seats for containing thedepressions in the band 5, which is thus well supported and guided atall times.

The conveyor 19 comprises a band 23 supported by rollers 24 and 25,which moves in synchronism with the band comprising the depressions,i.e., it moves with intermittent motion with steps equal to the pitch ofthe depressions on the band and with an adjustable frequency. It shouldbe noted that even at relatively low frequency a high production rate ispossible, because the number of pieces produced in a unit of time isequal to said frequency multiplied by the number of depressions presentin one transversal row of the band.

This number can be of any size within reasonable limits and in any casedepends directly on the average size of products to be packaged. In thecase shown the band, as stated, comprises four depressions disposed onebeside another.

At the extremity of the band 23, i.e., in a position correspondingapproximately with that of the roller 25, there is the vacuum assembly2. Said vacuum assembly 2 consists in effect of two units strictlylinked one with the other, one of which evacuates the packages, theother closing them by welding. The assembly 2 comprises a plate 26 whichremains downstream of the conveyor l9 and slightly removed from it,incorporating a series of longitudinal ribs 27 (FIG. 4) which standupwards and are of height equal to the maximum depth of the depressionsformed in the band 5. These ribs are distanced apart so as to supportthe flat parts of the band which lie between adjacent depressions andthe lateral edges of the band comprising the depressions. Said ribs actas guides for retaining the band transversally and as backing plates forthe welding assemblies. In addition to said ribs 27 the assembly 2comprises (FIGS. 2 and 3) two welders 28 and 29. The first of saidwelders, 28, comprises a working, i.e., heating, part 30 which on cominginto contact with the material forming the package, welds it in themanner described hereinafter. Said working part 30 comprises a series ofwelding members 30a, 30b, 30c, 30d and 30e disposed longitudinally andof length equal to one package, and of which the two external members,30a and 30e, are staggered in such a manner that they are slightlyupstream of the others. The working parts of said first welder aresupported by a support 31 rigid with a shaft 32 disposed above andtransversal to the band, and supported by supports 33 and 34. An arm 35is connected to said shaft external to the support 33, and is alsoconnected to cams which move in cycle with the other members of themachine.

On said shaft 32 is mounted a tubular shaft 36 which supports a member37 to which arms 38 are connected supporting the Working part 380 of thesecond welder, which operates transversal to the band and consequentlyextends between the two external members 300 and 30e of said firstwelder.

The arms 38 also support a presser 39 slightly down stream of thewelder, consisting of a transversal bar 40 lowerly packed with resilientmaterial. The bar 40 is provided with pivots 40a pointing upwards fromits back which are inserted into suitable seats in the arms 38. Betweenthe lower surfaces of said seats and the bar 40 there are springs 40bwhich maintain the bar pressed downwards.

A backing member 41 co-operates with the working part 380 of thetransversal welder 29 and is supported by rods 42 which slide in seats43 and are connected by levers to cams which cause them to rise and fallin cycle with said second welder, for letting the band 5 withdepressions to pass forward.

The pressing bar 40 is permanently in contact with a band 44 which windson a reel 45 and covers the band 5, and when welded to this latter formsthe required package.

The band 44 winds partially on a roller 46 which is supported by arms 47which support the evacuation aspirator described hereinafter.

The aspirator, 48, comprises a pipe 49 rigid with the ends of the arms47 and a flexible pipe and suitable valve means for connecting it to asuction pump of conventional type.

The pipe 49 comprises a series of holes 50 which connect its interiorwith the interspace 51 of a suction port or mouth comprising a pair ofplates 52 and 53 of width equal to the distance between the externalmembers of the first welder 28, and which remain permanently between thebands 5 and 44.

The arms 47 are connected at their other ends to arms 54 of levers 55which are operated by cams and which determine a forward and backwardmovement of said aspirator by the intermediate lever mechanism.

The aspirator rests on a member 56 disposed transversally over the band5 as a bridge. More precisely, the member 56 consists of a pair ofshoulders 56a and 56b and a laminar part 57 which joins them and onwhich the aspirator rests. The two said shoulders lowerly slide invertical guides 57a and are driven by cam means cooperating with leversand connecting rods. The machine is completed by cutting assemblies 3and 4, the first comprising a series of pairs of circular blades 60 and61 which act longitudinally along the welding lines between adjacentdepressions, whereas the second separates the various packagestransversally. Said second assembly consists of a blade 62 co-operatingwith a fixed counter blade 63. The blade 62 is supported on a support 64connected to the end of one arm of a rocking lever, the other arm ofwhich is connected by connecting rods to a cam. The circular blades ofthe assembly 3, the roller 25 of the conveyor 19 and the roller 18 areconnected to a source of rotary motion by means, for example abrake-friction clutch assembly, which provide an intermittent motion ofamplitude variable according to the length of the packages.

Operation of the machine described is as follows. At the assembly 1,that part of the band 5 lying between the members 7 and 8 is heated andafter having attained a plastic state predetermined for example by meansof a timer, the interior of the member 7 is connected to the inlet of apump and depressions are thus moulded in the band 5. After thismoulding, the members 7 and 8 open, the first to allow the band toadvance and the second so as not to heat parts which do not have to beheated. After the members 7 and 8 are opened the band 5 advances by alength equal to the pitch of the depressions. The 4 depressions soformed reach the conveyor 19 after a certain number of steps and duringthe time they remain on it the products to be packaged are introduced,into them.

As the band 5 advances along the machine, the series of depressionsunder consideration arrives at a certain point under the bridge member56 which, during movement of the band, is raised. When the forward stepof the band terminates the bridge member is lowered until it reaches thelevel shown in FIG. 2, and if the products introduced into thedepressions are greater in height that the depth of the depressions,this movement lowers the products until they are brought in line withthe edge of the depressions. After the bridge member 56 has beenlowered, and with it the aspirator which rests on it, the lever 54 isoperated by the corresponding cam and this initiates a backward movementof the aspirator 48 and hence also of the roller 46 on which the secondband 44 winds, and simultaneously initiates the descent of thetransversal welder 29 which as it acts on its backing member 41transversally joins the two bands 5 and 44. When the transversal weldhas been made the bands advance by one step and the depressions underconsideration pass downstream of the backing member 41 and occupy theircorrect position on the plate 26. During said advancement the bridgemember is in the raised position and the backing member 41 hasdescended. On termination of said advancement the backing member 41rises and the bridge member descends, and the welder 28 with its weldingmembers 30a, 30b, 30c, 30d and 302 joins the bands 5 and 44 alonglongitudinal lengths. When said welds are made the aspirator 48 isoperated and acts on the group of depressions under considerationremaining partially within the external welding lines (FIG. 3) becauseof which its action is efficient and rapid even with pumps of relativelysmall capacity. After a certain time the aspirator while still workingwithdraws unitl it passes the line of the transversal welder 29 whichdescends and closes the group of packages. The presser 40 during thisstage guarantees a good seal between the aspirator and band 44. Duringsuccessive advancement of the bands 5 and 44, the longitudinal welders28 complete the separation between the packages which are already closedto atmosphere, by completing the welding lines between one and theother, which is carried out by the end part of the longitudinal welders30b, 30c and 30d. After a certain number of steps the packages underconsideration arrive at the cutting assemblies 3 and 4 and are dividedby these.

From the aforegoing description it is clear that with the machineaccording to the invention it is possible to treat products which arealso sensitive to heat because of the small rise in temperature producedby welders in free air, which is impossible with chamber machines. It isalso clear that if products of small thickness, such as sliced meats,are to be packaged, it is not necessary to premould the lower band 5,the action of the bridge member 56 being sufficient to make theaspirator and welders operate correctly.

I claim:

1. A machine for vacuum packaging various products in particular foodproducts including means for supporting and guiding a pair of bandswhich approach each other longitudinally and fold the packages, weldingmembers lowered onto and raised from the bands for welding themtransversally and longitudinally after introducing the products betweenthem, and means for cutting the individual packages, a suction port offlat structure arranged upstream of the transversal welding member andpenetrating between the approaching portions of the bands welded alongtheir lateral edges, means for driving said port with reciprocatingmotion parallel to the bands and cooperating with the means whichoperate the transversal welding members so as to withdraw the suctionport during lowering of said welding members, wherein according to theimprovement, the machine further comprises an assembly for moulding, inat least one of the bands, depressions for receiving products, a plateprovided below the longitudinal welding members for supporting the bandprovided with depressions, said plate comprising ribs having a hightsubstantially equal to that of the depressions and acting as backingmembers for said longitudinal welding members, a flat transversal membermovable in a vertical plane behind said plate and acting in the raisedposition as a backing member for the transversal weld ing member, cammeans for driving said welding members through levers and connectingrods.

2. A machine as claimed in claim 1 in which the longitudinal weldingmembers and transversal welding members are supported on arms whichproject respectively from shaft supported on the upper part of themachine downstream of the working zone of the welding members and from atubular shaft rotatably mounted coaxially of the former, the two saidshafts also comprising arms on which cams act by way of interposedlevers and connecting rods for driving the welders.

3. A machine as claimed in claim 1 in which said suction port comprisesa pair of plates joined together so as to define a slot and of widthequal to the distance be tween the external longitudinal welding membersand which project tangentially from a tube having perforations inpositions corresponding with said slot and connected by way of aflexible tube and valve means to a pump, and in which said tube is fixedto arms which in their turn are pivoted to the extremities of leverscontrolled through connected rods by cams so as to cause the forward andbackward movement of the suction port, on said arms there being pivoteda roller on which the upper band of the package partially winds pressedagainst the upper plate of said suction port by a presser, said suctionport laying on a bridge member transversally arranged above the bandprovided with depressions which slides in vertical guides and is drivenvertically by cam means.

1. A machine for vacuum packaging various products in particular foodproducts including means for supporting and guiding a pair of bandswhich approach each other longitudinally and fold the packages, weldingmembers lowered onto and raised from the bands for welding themtransversally and longitudinally after introducing the products betweenthem, and means for cutting the individual packages, a suction port offlat structure arranged upstream of the transversal welding member andpenetrating between the approaching portions of the bands welded alongtheir lateral edges, means for driving said port with reciprocatingmotion parallel to the bands and cooperating with the means whichoperate the transversal welding members so as to withdraw the suctionport during lowering of said welding members, wherein according to theimprovement, the machine further comprises an assembly for moulding, inat least one of the bands, depressions for receiving products, a plateprovided below the longitudinal welding members for supporting the bandprovided with depressions, said plate comprising ribs having a hightsubstantially equal to that of the depressions and acting as backingmembers for said longitudinal welding members, a flat transversal membermovable in a vertical plane behind said plate and acting in the raisedposition as a backing member for the transversal welding member, cammeans for driving said welding members through levers and connectingrods.
 2. A machine as claimed in claim 1 in which the longitudinalwelding members and transversal welding members are supported on armswhich project respectively from shaft supported on the upper part of themachine downstream of the working zone of the welding members and from atubular shaft rotatably mounted coaxially of the former, the two saidshafts also comprising arms on which cams act by way of interposedlevers and connecting rods for driving the welders.
 3. A machine asclaimed in claim 1 in which said suction port comprises a pair of platesjoined together so as to define a slot and of width equal to thedistance between the external longitudinal welding members and whichproject tangentially from a tube having perforations in positionscorresponding with said slot and connected by way of a flexible tube andvalve means to a pump, and in which said tube is fixed to arms which intheir turn are pivoted to the extremities of levers controlled throughconnected rods by cams so as to cause the forward and backward movementof the suction port, on said arms there being pivoted a roller on whichthe upper band of the package partially winds pressed against the upperplate of said suction port by a presser, said suction port laying on abridge member transversally arranged above the band provided withdepressions which slides in vertical guides and is driven vertically bycam means.